240v goes to 1 and 4. (Active goes to 1, neutral goes to 4.) Bridge 2 to 3 (solder a wire from 2 to 3)
just to be clear to any one else who refers to this, A. make sure the machine is unplugged from the 240v power outlet. & B. when we say 'bridge' between 2 & 3 we mean solder a wire across these two terminals not solder a bridge rectifier.
Also I dont think used MOV's back then but in solid state machines when they did use them, make sure it is changed to a 275 volt MOV.
I think you may also have to change the value of the mains fuse. Can some one confirm this please. If you do then you will have to half the value of the current fuse they used for 110v and make sure it's a slow blow type, rated at 240 volts. again check this with the machine unplugged from the wall.
Yes - main fuse needs to be changed... the wattage value of original and new should be the same